Larry Vega saw the attack and watched as police arrived, ordered the attacker to stop, and described what happened next. "He said 'get off,' told him several times, and the guy just stood, his head up like that with a piece of skin hanging out of his mouth," he said.

When the attacker didn't stop, the officer shot and killed him. Miami medical experts believe the man was most likely under the influence of synthetic drugs, like bath salts or fake marijuana -- the same drugs Florida Poison Control in Tampa warns against.

10 News acquired official police pictures of the attacker and the eaten victim at the crime scene, and showed them to Cynthia Younger M.D., the doctor who runs that Tampa department.

Dr. Younger said new synthetic drugs called synthetic cathinones have been known to cause violent, psychotic behavior, and may explain the attack.

"Any drug that causes an effect, either a high or a low, goes through a membrane called the blood-brain barrier into the brain and changes the chemicals."

Dr. Younger said these changes can manifest themselves in many behaviors, some violent, so special warnings go out to parents that synthetic drugs can be just as, sometimes even more dangerous than, drugs like Xtacy and crystal meth, and they need to be discussed.

"We should at least be saying 'this is not OK, you can hurt yourself."